Friday, February 27, 2009

The Iowa Department of Natural Resources (DNR) has extended the public comment period on the proposed antidegradation rules to March 4. The antidegradation policy, required by Iowa law, would set minimum requirements for the conservation, maintenance and protection of water quality and existing uses of surface waters.

Antidegradation policy is one of the three components of water quality standards - 1) designated uses, 2) water quality criteria to protect those uses, and 3) antidegradation policy). The DNR is proposing a four-tiered approach, including creating a guidance document that establishes procedures for implementing the antidegradation policy.

The changes being proposed include the following:

Incorporate by reference the document entitled “Iowa Antidegradation Implementation Procedure,” which proposes an approach to be followed in assessing and minimizing degradation of Iowa’s surface waters

Update antidegradation policy language with four tier approach, and

Remove High Quality (Class HQ) and High Quality Resource (Class HQR) designated uses and add several waters to the newly proposed Outstanding Iowa Water (OIW) category.

Caltha LLP provides specialized expertise to clients nationwide in the evaluation and use of ambient water quality criteria, site-specific water quality standards, and permit limits. Caltha staff have prepared national Ambient Water Quality Criteria for US EPA and provide expert resources for permittees and/or their technical consultants as they address State and Federal water quality standards.